{"schemaVersion":"cwiki-fiche-1.0","identifiers":{"inchiKey":"IYRMWMYZSQPJKC-UHFFFAOYSA-N","prefName":"Kaempferol","symbol":"Kaempférol","iupacName":"3,5,7-trihydroxy-2-(4-hydroxyphényl)chromén-4-one","aliases":["kaempferol","3,4',5,7-tétrahydroxyflavone","campherol","robigenin"],"cas":"520-18-3","pubchemCid":"5280863","chebiId":null,"smiles":"C1=CC(=CC=C1C2=C(C(=O)C3=C(C=C(C=C3O2)O)O)O)O","molecularFormula":"C15H10O6","molecularWeight":286.24,"xrefs":{"pubchem":"https://pubchem.ncbi.nlm.nih.gov/compound/5280863"}},"classification":{"family":"ecs_tool","familyLabel":"ECS modulator (research)","origin":"synthetic","originLabel":"Synthétique","structuralClassFr":"Flavonol, sous-classe des flavonoïdes définie par un squelette 2-phénylchromén-4-one portant un hydroxyle en position 3. La molécule présente quatre fonctions phénoliques, réparties en 3, 5, 7 sur le noyau chromone et en 4' sur le cycle phényle pendant. C'est cette combinaison d'un hydroxyle en 3 et d'un hydroxyle en 7 qui gouverne l'activité sur l'amidohydrolase, comme le montre la puissance supérieure de la 3,7-dihydroxyflavone dépouillée des autres substituants."},"originSynthesis":{"heading":"Origin (research tool)","summaryFr":"A flavonol arising from the phenylpropanoid route. Phenylalanine is converted into cinnamic acid then into coumaroyl-coenzyme A, which condenses with three units of malonyl-coenzyme A under the action of chalcone synthase. The chalcone obtained is cyclised into a flavanone, then hydroxylated and desaturated to give the flavonol. That route is proper to plants and bears no relation to the biosynthesis of the hemp cannabinoids.","originNote":"A flavonol very widespread in the plant kingdom, present notably in capers, kale, spinach, broccoli, tea and many medicinal plants, most often as glycosides that digestive hydrolysis releases. It forms part of the ordinary daily dietary intake of polyphenols.","discovered":"Flavonol connu de longue date comme pigment végétal et étudié pour ses propriétés antioxydantes. Son rattachement au système endocannabinoïde date de 2008, quand Thors, Belghiti et Fowler, à l'université d'Umeå, ont criblé une vingtaine de flavonoïdes sur l'hydrolyse de l'anandamide et l'ont identifié comme le plus puissant des flavonoïdes d'occurrence courante sur cette cible."},"pharmacology":{"summaryFr":"Kaempferol is a common dietary flavonol whose endocannabinoid interest rests on an indirect mechanism. It has no affinity for CB1 and CB2 receptors: it acts on fatty acid amide hydrolase, the enzyme that hydrolyses anandamide and therefore sets the lifetime of that endocannabinoid. Thors, Belghiti and Fowler screened twenty compounds against that target in 2008 and found it the most potent of the widely distributed natural flavonoids, with competitive-type inhibition and an inhibition constant of 5 micromolar. The same work showed that the effect holds on intact basophilic leukaemia cells, where the compound reduces anandamide uptake and its metabolism, and identified two flavonoids of more restricted distribution that are more active still, 7-hydroxyflavone and 3,7-dihydroxyflavone, with median inhibitory concentrations below the micromolar. That work follows on from the studies devoted to the isoflavones genistein and daidzein, active on the same enzyme in the same concentration range. The physiological reach of these results nevertheless calls for restraint: the effective concentrations lie in the micromolar range, far above the plasma concentrations attained after a flavonoid-rich meal, whose absorption and first-pass metabolism are moreover limiting. The compound is worth more as a chemical starting point for designing inhibitors than as an established dietary mechanism of action.","receptorSummaryFr":"The compound is not a ligand of cannabinoid receptors. It acts upstream, on the enzyme that destroys anandamide: Thors and colleagues identified it as a competitive inhibitor of fatty acid amide hydrolase, with an inhibition constant of 5 micromolar, a value that makes it the most active of the common flavonoids tested in their series. Inhibition was confirmed on intact cells, where the compound reduces both the uptake of anandamide dependent on that enzyme and its metabolism. The expected effect is therefore an indirect elevation of endocannabinoid tone, and not a direct activation of the receptors.","binding":[{"target":"FAAH","efficacy":"antagonist","relativeActivity":40,"reported":"Ki = 5 µM, inhibition compétitive (Thors et coll. 2008)","confidence":"medium"},{"target":"CB1","efficacy":"modulator","relativeActivity":5,"reported":"Effet indirect via l'élévation de l'anandamide ; pas de liaison directe","confidence":"medium"}],"references":[{"label":"Thors et coll. 2008 : inhibition de la FAAH par le kaempférol et des flavonoïdes naturels apparentés","pmid":"18552875","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/18552875/"},{"label":"Thors et coll. 2007 : inhibition de la captation cellulaire de l'anandamide par la génistéine et la daidzéine","pmid":"17676056","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/17676056/"}]},"pharmacokinetics":"L'absorption orale est faible et fortement conditionnée par la forme d'apport, la molécule circulant dans les végétaux sous forme de glycosides qui doivent être hydrolysés avant absorption. Le métabolisme de premier passage intestinal et hépatique est intense, si bien que les concentrations plasmatiques de l'aglycone libre restent de l'ordre du nanomolaire au submicromolaire après un apport alimentaire, soit très en deçà des concentrations actives mesurées in vitro sur l'amidohydrolase.","metabolism":"Le composé subit une conjugaison rapide et étendue, par glucuronidation et sulfatation, dans l'entérocyte puis dans l'hépatocyte. Une fraction importante échappe à l'absorption dans l'intestin grêle et parvient au côlon, où le microbiote la dégrade en acides phénoliques de faible masse, lesquels constituent une part notable des métabolites circulants. Cette transformation extensive complique l'attribution d'un effet observé in vivo à la molécule intacte.","detection":"Le dosage s'effectue par chromatographie liquide couplée à la spectrométrie de masse en tandem, généralement après hydrolyse enzymatique des conjugués pour mesurer l'aglycone total. Le composé n'appartient à aucun panel toxicologique et n'a pas d'intérêt médicolégal ; sa mesure relève de la nutrition et de l'épidémiologie des polyphénols.","subjectiveEffects":{"profile":[{"key":"calm","label":"Calm","description":"Relaxation of body and mind; reduced mental noise without marked drowsiness.","intensity":25},{"key":"focus","label":"Clarity","description":"Sustained attention and clear thinking; functional lucidity, not euphoria.","intensity":15},{"key":"sleep","label":"Sleep","description":"Sedative effect: aids sleep onset and the continuity of deep sleep.","intensity":15},{"key":"appetite","label":"Appetite","description":"Stimulation of hunger and of taste appreciation (the “munchies” effect).","intensity":5},{"key":"uplift","label":"High","description":"Euphoria and sensory intensity; altered perception of time and space.","intensity":15}],"doseRanges":null,"humanDataCharacterised":true},"indications":{"approvedMedicines":[]},"harmProfile":{"unstudiedBanner":false,"bannerTextFr":null,"toxicologyFr":"Aucun événement toxique n'est documenté aux niveaux d'exposition alimentaire, qui sont ceux de la consommation ordinaire de légumes et de thé. Les extraits concentrés destinés à la supplémentation n'ont pas fait l'objet d'une caractérisation de sécurité comparable, et l'interaction potentielle des flavonoïdes avec les enzymes de métabolisation des médicaments justifie la prudence en cas de traitement concomitant. Aucune dose humaine à visée pharmacologique n'est caractérisée."},"legal":{"scheduleStatus":"unscheduled","scheduleLabel":"Unscheduled","frScheduleStatus":"unscheduled","tiers":[{"jurisdiction":"international","jurisdictionLabel":"International","label":"Non inscrit aux conventions de contrôle","reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null},{"jurisdiction":"eu","jurisdictionLabel":"Union européenne","label":"Constituant alimentaire naturel ; non contrôlé","reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null},{"jurisdiction":"fr","jurisdictionLabel":"France","label":"Non inscrit ; présent dans l'alimentation courante","reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null}],"sourcesFr":"EUR-Lex, UNODC, CND, ANSM, IUPHAR/BPS, ChEBI, EUDA."},"references":[{"label":"Thors et coll. 2008 : inhibition de la FAAH par le kaempférol et des flavonoïdes naturels apparentés","pmid":"18552875","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/18552875/"},{"label":"Thors et coll. 2007 : inhibition de la captation cellulaire de l'anandamide par la génistéine et la daidzéine","pmid":"17676056","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/17676056/"}],"meta":{"slug":"kaempferol","url":"https://en.phytogrammes.com/wiki/kaempferol","lastVerified":"2026-05-01","dataUpdatedAt":"2026-08-16","confidence":"medium","dataCompletenessPct":90,"disclaimerFr":"Contenu éditorial informatif, sans valeur d'avis médical ni juridique. Sources primaires citées par fiche. Réservé aux adultes."}}